US20110056047A1

US20110056047A1 - Back carried work apparatus

Info

Publication number: US20110056047A1
Application number: US12/923,150
Authority: US
Inventors: Harald Schliemann; Klaus Langhans
Original assignee: Andreas Stihl AG and Co KG
Current assignee: Andreas Stihl AG and Co KG
Priority date: 2009-09-08
Filing date: 2010-09-07
Publication date: 2011-03-10
Also published as: CN102011371A; DE102009040493A1

Abstract

A back carried work apparatus has a back carrier (2) with a back carrier plate (15). The back carrier plate (15) extends in an upward direction (21) and in a lateral direction (41) when the back carrier (2) is arranged on the back of an operator (14). A drive motor (8) is arranged on the back carrier (2) and rotatably drives a blower wheel (9) about a rotational axis (11) arranged transversely to the back carrier plate (15). The blower wheel (9) moves an air flow through the blower spiral (10) and blower tube (12) connected to the blower output (23) of the blower spiral (10). A simple configuration results when the blower tube (12) is pivotally mounted about a pivot axis (25) which extends in the lateral direction (41) of the back carrier plate (15).

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority of German patent application No. 10 2009 040 493.7, filed Sep. 8, 2009, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a back carried work apparatus.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 7,774,896 discloses a back carried blower which has a blower tube arranged at the output of the blower spiral. The blower tube extends sideways and obliquely downwards away from the blower spiral. During operation, the blower tube is pivoted laterally, that is, to the left and to the right from the operator's perspective, as well as up and down. A bellows is provided in known back carried work apparatus to make this movement possible. To enable the lateral and the up and down pivot motions, the bellows section of the blower tube has to be comparatively long.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a back carried work apparatus of the kind described above, which has a simple configuration.
The back carried work apparatus of the invention includes: a back carrier having a back carrier plate extending in an up direction and a lateral direction when the back carrier is arranged on an operator's back; a drive motor arranged on the back carrier; a blower wheel defining a rotational axis extending transversely to the back plate; the drive motor being configured to rotatably drive the blower wheel about the rotational axis; a blower spiral having a blower output; a blower tube connected to the blower output and being mounted thereon so as to pivot about a pivot axis extending in the lateral direction of the back carrier plate; and, the blower wheel being configured to move air so as to cause an air flow through the blower spiral and through the blower tube.
Because the blower tube is pivotally mounted about a pivot axis which extends laterally, an upward/downward pivot motion can be performed via the pivot bearing of the blower tube. Thereby, an initial setting of the arrangement of the blower can be set via the pivot bearing of the blower tube. Thus, for example, a presetting according to the size of the operator can be made. During operation, small movements can advantageously be realized via a flexible section of the blower tube, for example, via a bellows section. Lateral movements can also be performed via this flexible section. As a result of the arrangement of the pivot bearing, the blower tube can be arranged upwardly for transport and advantageously projects about vertically upwards. Thereby, a space saving arrangement of the blower tube results for transport. If large pivot movements are required during operation, they can be partially or entirely made via the pivot bearing. It can also be provided that also small upward and downward movements during operation are made via the pivot bearing.
A simple embodiment is achieved when the blower tube is pivotally mounted on the blower output. The lateral orientation of the blower output can easily be achieved via a blower wheel with a rotational direction which is opposite to the rotational direction of common back carried work apparatus. For this purpose, the blower wheel rotates counterclockwise when viewed in a direction from the drive motor toward the back carrier plate.
Advantageously, the back carrier includes a base plate. The flow direction in the blower output thereby advantageously runs approximately parallel to the plane of the base plate, during operation especially approximately horizontal. In this way, a pivot motion of the blower tube in the vertical direction is made possible. In the transport state, the blower tube can thereby stand vertically upwards. An advantageous arrangement is achieved when the blower output is arranged immediately above the base plate in relation to the upward direction. This enables ergonomic working.
A simple embodiment is achieved when the blower tube includes a connector part which connects to the blower output and redirects the air flow. The flow direction in the inlet cross-section of the connector part and the flow direction of the output cross-section thereby conjointly define an angle between about 75° and 115° . An angle in the range of about 85° to about 105° has been shown to be especially advantageous. An angle (a) little larger than 90° has been shown to be advantageous. Thereby, the blower tube can be guided laterally around the operator in close proximity to the operator. The connector part is, in particular, pivotally mounted on the blower output. Advantageously, the connector part is rigid. The blower tube includes a bellows section to also allow for a lateral pivot movement of the blower tube. Advantageously, the connector part is formed integrally with the bellows section. In this way, the connector part can be made of a rigid material and be formed on the bellows section. The connector part can, however, also be flexible. The connector part can, however, also be a separate component. Advantageously, the bellows section is arranged downstream of the connector part. A bellows section, which redirects the air flow, can, however, also be connected to the blower output.
The proposed pivotal mounting of the blower tube is especially advantageous in the case of a work apparatus in which the blower inlet is arranged on the side of the blower wheel that faces toward the back carrier plate and is aligned axially to the rotational axis of the blower wheel. Accordingly, the blower wheel draws in in the axial direction and moves the air radially toward the outside and into the blower spiral. Advantageously, a plurality of intake openings are arranged between the back carrier plate and the blower spiral. In this area, the contamination of the ambient air through whirled-up dust particles or the like is low, so that few contaminants, which might clog or damage the intake openings, are drawn in.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawings wherein:

FIG. 1 is a side elevation view of a blower apparatus carried on an operator's back;

FIG. 2 is a side elevation view of the blower apparatus of FIG. 1 seen in the direction of the arrow II in FIG. 1;

FIG. 3 is an enlarged view of the blower apparatus with the view from FIG. 2;

FIG. 4 is a side view of the blower apparatus of FIG. 3 seen in the direction of arrow IV from FIG. 3;

FIG. 5 is a section view of a blower apparatus in the direction of arrow V-V from FIG. 3;

FIG. 6 is a schematic side view of the connector part of the blower tube; and,

FIG. 7 is a side view of an alternate embodiment of a blower apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows a back carried blower 1 as an example embodiment of the back carried work apparatus. The blower 1 has a back carrier 2, which is carried by an operator 14 shown schematically in FIGS. 1 and 2 on the operator's back with two shoulder straps 3 and 4 (FIG. 2). The back carrier 2 has a back carrier plate 15, which rests on the back of the operator 14 with a cushion, which is not shown. The back carrier 2 also has a base plate 16 which extends transversely to the back carrier plate 15, in particular, perpendicularly to the back carrier plate 15.
A housing 5 is arranged on the back carrier 2, in which a drive motor 8, schematically shown in FIG. 2, is arranged. A start handle 6 for the drive motor 8 projects out of the housing 5. A fuel tank 7 is arranged below the housing 5. The fuel tank 7 can also be integrated in the housing.
The blower 1 has a blower tube 12, through which work air is conveyed during operation. An operating handle 13, with which the operator 14 can guide the blower tube 12 with his hand 20, is fixed on the blower tube 12. The blower tube 12 includes a connector part 24 which is pivotally mounted about a pivot axis 25. Thereby, the entire blower tube 12 can be pivoted up and down in the direction of the double arrow 38. A bellows section 30 is provided downstream of the connector part 24. The bellows section 30 enables lateral movements and an up and down pivot motion of the operating handle 13 and thereby of the output opening 39 provided downstream of the blower tube 12. The pivot movement of the blower tube 12, which results from the pivotal arrangement of the connector part 24, advantageously serves to enable a preset position of the blower tube 12 corresponding to the size of the operator. The pivot motion about the pivot axis further makes it possible to set the blower tube 12 upwardly for transport, so that the blower tube advantageously projects vertically. Thereby, a space saving transport is possible. During operation small lateral as well as small up and down movements can be made as a result of elastic deformation of the bellows section 30. Very large pivot movements up and down in the direction of the double arrow 38 can be made possible by the bellows section 30; large movements can, however, also be performed by pivoting the connector part 24.
The connector part 24 can be formed as a separate component which is connected to the bellows section 30 and to the housing 5 of the blower 1. The connector part 24 can, however, also be integral with the bellows section 30. In the embodiment shown the connector part 24 has smooth walls. The connector part is thereby rigid. The connector part 24 can, however, also be made of a flexible material. In the arrangement shown in FIGS. 1 and 2, the connector part 24 can also be formed integrally with the bellows section 30, for example, molded onto the bellows section 30.
As FIGS. 1 and 2 show, the back carrier plate 15 extends in an upward direction 21 which is advantageously vertical as well as in a lateral direction 41, which is in the lateral direction of the operator 14 and perpendicular to the upward direction 21, when the back carrier 2 is arranged on the back of the operator 14. The back carrier plate 15 thus extends about parallel to the back of the operator 14. The base 19 of the base plate 16 extends about perpendicularly to the back carrier plate 15 and advantageously in the direction of a horizontal line H. The horizontal line H defines a horizontal plane when the operator stands upright. The lateral direction 41 is parallel to this plane. As FIG. 2 shows, the pivot axis 25 extends in the lateral direction 41 and parallel to the horizontal line H.
The fuel tank 7 is arranged between the housing 5 and the base plate 16 in relation to the upward direction 21. A suction head 18, which conveys fuel to the drive motor 8, is arranged in the fuel tank 7. The drive motor 8 is configured as a single-cylinder combustion engine. As FIG. 2 shows, the back carrier 2 has a handle 17 on the back carrier plate 15 with which the back carrier 2 can be carried.
A blower wheel 9 is arranged in the housing 5 as is shown schematically in FIG. 3. The blower wheel 9 rotates about a rotational axis 11 in a direction of rotation 22. The rotational axis 11 is perpendicular to the plane 35 defined by the back plate 15 and shown in FIG. 4. The plane 35 thus extends in the upward direction 21 and the lateral direction 41. The blower wheel 9 conveys the work air into a blower spiral 10 which extends along the periphery of the blower wheel 9. The blower spiral 10 thereby enlarges in the rotational direction. The blower output 23 from the blower spiral 10 is to the side of the base plate 16 and immediately above the base plate 16.
As FIG. 3 shows, the connector part 24 is arranged on the blower output 23. The connector part 24 is thereby held on the blower output 23 pivotally about the pivot axis 25. The connector part 24 is advantageously rigid, especially made of plastic. The connector part 24 can, however, also be made at least partially of an elastic material. The connector part 24 is advantageously detachably mounted on the blower output 23, for example, clipped into the blower spiral 10, so that the blower tube 12 can be removed for transport. The blower tube 12 can, however, also project vertically upwards for transport. The base plate 16 extends in a plane 37, which is advantageously about parallel to the horizontal line H during operation. The plane 37 is advantageously perpendicular to the plane 35 of the back carrier plate 15.
FIG. 4 shows the arrangement of the blower output 23 in the horizontal direction between the fuel tank 7 and the back carrier plate 15. A plurality of intake openings 36 for work air are provided between the housing 5 and the back carrier plate 15. As FIGS. 3 and 4 show, the connector part 24 is angled. The flow direction 34 in the output cross section 32 of the connector part 24 is oriented diagonally toward the front in the position of the blower tube 12 shown in FIG. 1.
FIG. 5 shows the setup of an embodiment of a blower 1 in detail. Thereby, the identical reference characters correspond to the same elements. The blower 1 has a start arrangement 28 for the drive motor 8. The start arrangement 28 is actuated by the operator 14 via the start handle 6. The drive motor 8 has a crankshaft 26 which is driven by the start arrangement during starting. A fan wheel 27 for moving cooling air for the drive motor 8 can be arranged between the crankshaft 26 and the start arrangement 28.
The blower wheel 9 is arranged on the end of the crankshaft 26 which is opposite to the start arrangement 28. The blower wheel 9 draws in work air via a blower inlet 29 in axial direction to the rotational axis 11. The blower inlet 29 is arranged between the blower wheel 9 and the back carrier plate 15 in the direction of the rotational axis 11. The blower spiral extends radially outside of the blower wheel. A plurality of intake openings 36 are arranged between the blower spiral 10 and the back carrier plate 15, via which ambient air is drawn in and conveyed into the blower spiral 10 by the blower wheel 9 configured as a radial blower.
FIG. 6 shows an embodiment of the connector part 24. The connector part 24 has an intake cross-section 31 which connects to the blower output 23. The flow direction in the intake cross-section 31 corresponds to the flow direction 33 in the blower output 23. The connector part 24 is formed in the shape of an arc of a circle and has an output cross-section 32 through which the work air flows in a flow direction 34. The connector part 24 redirects the air flow conveyed by the blower wheel 9. The flow direction 33 in the intake cross-section 31 and the flow direction 34 in the output cross-section 32 conjointly define an angle (a) which advantageously is between about 75° and about 115° , and in particular between about 85° and about 105° . It has been shown that an angle (a) of a little larger than 90° is especially advantageous.
Because of the pivotal arrangement of the entire blower tube 12 on the blower output 23 which is fixed to the housing, the blower tube 12 can be pivoted in the direction of the double arrow 38 (FIG. 1) via the pivot bearing of the connector part 24, so that an advantageous transport position results and a presetting of the position of the blower tube, for example to correspond to the size of the operator, is possible. The pivot bearing can also have a lock-in position in the vertically upwards position of the blower tube, so that the blower tube 12 can lock-in fixed in a transport position. This is simply achieved via the horizontal orientation of the blower output 23, which is especially made possible by the reversal of the blower rotation direction 22. Thereby, a simple configuration of the blower 1 results.
FIG. 7 shows an alternative embodiment of the blower, in which a bellows section 40, which redirects the air flow, connects to the blower output 23. The bellows section 40 is directly connected to the blower output 23 and is pivotal hereon about the pivot axis 25. As a result of the pivotal arrangement of the bellows section 40 on the blower output 23 the presetting of the position of the blower tube 12 according to the size of the operator can be achieved, so that comparatively few deformations of the bellows section 40 must occur during operation. For transport, the bellows section 40 can be twisted on the blower output 23, so that the blower tube 12 projects into a desired direction for space saving transport. The bellows section 40 is connected downstream with a rigid section of the blower tube 12 on which the handle 13 is also fixed.
It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A back carried work apparatus comprising:

a back carrier having a back carrier plate extending in an up direction and a lateral direction when said back carrier is arranged on an operator's back;

a drive motor arranged on said back carrier;

a blower wheel defining a rotational axis extending transversely to said back plate;

said drive motor being configured to rotatably drive said blower wheel about said rotational axis;

a blower spiral having a blower output;

a blower tube connected to said blower output and being mounted thereon so as to pivot about a pivot axis extending in said lateral direction of said back carrier plate; and,

said blower wheel being configured to move air so as to cause an air flow through said blower spiral and through said blower tube.

2. The back carried work apparatus of claim 1, wherein said blower tube is pivotally mounted on said blower output.

3. The back carried work apparatus of claim 1, wherein, in the viewing direction from said drive motor toward said back carrier plate, said blower wheel rotates in a counterclockwise direction.

4. The back carried work apparatus of claim 1, wherein said back carrier has a base plate.

5. The back carried work apparatus of claim 4, wherein said base plate defines a base plane and said air flow defines a flow direction in said blower output approximately parallel to said base plane.

6. The back carried work apparatus of claim 4, wherein said blower output is arranged immediately above said base plate referred to said up direction.

7. The back carried work apparatus of claim 1, wherein said blower tube has a connecting part connected to said blower output and to redirect said air flow.

8. The back carried work apparatus of claim 7, wherein said connecting part has an intake cross section and a output cross section through which there is a first flow direction of said air flow and a second flow direction of said air flow respectively;

and, said first flow direction and said second flow direction conjointly define an angle (a) in the range of about 75° to about 115° .

9. The back carried work apparatus of claim 7, wherein said connecting part is rigid.

10. The back carried work apparatus of claim 7, wherein said blower tube has a bellows section.

11. The back carried work apparatus of claim 10, wherein said connecting part is formed as a one-piece with said bellows section.

12. The back carried work apparatus of claim 10, wherein said connecting part is a separate component.

13. The back carried work apparatus of claim 10, wherein said bellows section is arranged downstream of said connecting part.

14. The back carried work apparatus of claim 1, further comprising a bellows section connected to said blower output redirecting said air flow.

15. The back carried work apparatus of claim 1, further comprising a blower intake arranged on the side of said blower wheel facing said back carrier plate and said blower intake being axially aligned to said rotational axis of said blower wheel.

16. The back carried work apparatus of claim 1, further comprising a plurality of intake openings arranged between said back carrier plate and said blower spiral.